title: Radiation lobectomy: time-dependent analysis of future liver remnant volume in unresectable liver cancer as a bridge to resection.
abstract: OBJECTIVE
  Portal vein embolization (PVE) is a standard technique for patients not amenable to liver resection due to small future liver remnant ratio (FLR). Radiation lobectomy (RL) with (90)Y-loaded microspheres (Y90) is hypothesized to induce comparable volumetric changes in liver lobes, while potentially controlling the liver tumor and limiting tumor progression in the untreated lobe. We aimed at testing this concept by performing a comprehensive time-dependent analysis of liver volumes following radioembolization.
  
  
  METHODS
  83 patients with right unilobar disease with hepatocellular carcinoma (HCC; N=67), cholangiocarcinoma (CC; N=8) or colorectal cancer (CRC; N=8) were treated by Y90 RL. The total liver volume, lobar (parenchymal) and tumor volumes, FLR and percentage of FLR hypertrophy from baseline (%FLR hypertrophy) were assessed on pre- and post-Y90 CT/MRI scans in a dynamic fashion.
  
  
  RESULTS
  Right lobe atrophy (p=0.003), left lobe hypertrophy (p<0.001), and FLR hypertrophy (p<0.001) were observed 1 month after Y90 and this was consistent at all follow-up time points. Median %FLR hypertrophy reached 45% (5-186) after 9 months (p<0.001). The median maximal %FLR hypertrophy was 26% (-14 → 86). Portal vein thrombosis was correlated to %FLR hypertrophy (p=0.02). Median Child-Pugh score worsening (6 → 7) was seen at 1 to 3 months (p=0.03) and 3 to 6 months (p=0.05) after treatment. Five patients underwent successful right lobectomy (HCC N=3, CRC N=1, CC N=1) and 6 HCCs were transplanted.
  
  
  CONCLUSIONS
  Radiation lobectomy by Y90 is a safe and effective technique to hypertrophy the FLR. Volumetric changes are comparable (albeit slightly slower) to PVE while the right lobe tumor is treated synchronously. This novel technique is of particular interest in the bridge-to-resection setting.
authors.affiliation: Department of Radiology, Section of Interventional Radiology and Division of Interventional Oncology, Northwestern University, Chicago, IL, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Vouche
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lewandowski
authors.forename: Rohi
authors.initials: R
authors.lastname: Atassi
authors.forename: Khairuddin
authors.initials: K
authors.lastname: Memon
authors.forename: Vanessa L
authors.initials: VL
authors.lastname: Gates
authors.forename: Robert K
authors.initials: RK
authors.lastname: Ryu
authors.forename: Ron C
authors.initials: RC
authors.lastname: Gaba
authors.forename: Mary F
authors.initials: MF
authors.lastname: Mulcahy
authors.forename: Talia
authors.initials: T
authors.lastname: Baker
authors.forename: Kent
authors.initials: K
authors.lastname: Sato
authors.forename: Ryan
authors.initials: R
authors.lastname: Hickey
authors.forename: Daniel
authors.initials: D
authors.lastname: Ganger
authors.forename: Ahsun
authors.initials: A
authors.lastname: Riaz
authors.forename: Jonathan
authors.initials: J
authors.lastname: Fryer
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Caicedo
authors.forename: Michael
authors.initials: M
authors.lastname: Abecassis
authors.forename: Laura
authors.initials: L
authors.lastname: Kulik
authors.forename: Riad
authors.initials: R
authors.lastname: Salem
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D018450:Disease Progression; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008099:Liver / Q000473:pathology* / Q000528:radiation effects / Q000601:surgery; D008113:Liver Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D009929:Organ Size; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D015021:Yttrium Radioisotopes
chemical_list: D015021:Yttrium Radioisotopes
keywords: %FLR hypertrophy; (90)Y-loaded glass microspheres radioembolization; AFP; CC; CP; CRC; CT; Child-Pugh; FLR; Future liver remnant; HCC; Hypertrophy; INR; Liver resection; MRI; PVE; PVT; RL; Radiation lobectomy; Radioembolization; Y90; alpha-fetoprotein; cholangiocarcinoma; colorectal cancer; computed tomography; hepatocellular carcinoma; international normalized ratio; magnetic resonance imaging; percentage increase in FLR hypertrophy from baseline; portal vein embolization; portal vein thrombosis; radiation lobectomy; ratio (expressed as percentage) of the future liver remnant (segments 2/3) to the total liver parenchymal volume